Do Jaw Deformities Adversely Affect Largemouth Bass?

Largemouth Bass Micropterus nigricans anglers have mainly adopted catch-and-release practices with limited direct fishing mortality. However, catch-and-release angling could cause delayed mortality and non-lethal effects that could potentially impact population dynamics. For instance, hooking can result in jaw deformities, with unknown subsequent effects on vulnerability to angling, condition, growth, and mortality. Our objectives were to assess the prevalence of Largemouth Bass jaw deformities and test for differences in angling vulnerability, growth, condition, size structure, and mortality of fish with and without jaw deformities. Largemouth Bass were captured by electrofishing and by anglers at 41 tournaments at Brushy Creek, Iowa between April and August 2015. Jaw deformities were observed in 7.0% of fish caught at tournaments and 3.3% caught while electrofishing (5.8% overall). Angling recapture rates of tagged fish with (78.9%) and without (76.8%) jaw deformities were similar. Condition, growth, size structure, and mortality of fish with and without jaw deformities were also similar. Our results indicate jaw deformities have little effect on Largemouth Bass angling vulnerability, condition, growth, or survival; however, we still recommend careful handling of fish to minimize injuries that may occur during angling.